Personal authentication is required for identification of persons as a protection against unauthorized access to information technology devices and the unauthorized utilization of card-based services. Conventionally, personal authentication has involved methods using passwords and personal identification numbers and biometric technologies using fingerprints and veins.
In general, personal authentication using related-art methods requires users to be authenticated again when a series of functions is used later after initial authentication because of timeouts due to the end of utilization by the user and the lapse of a predetermined time. This raises a problem in that password-based lock functions, such as those performed by information management, are actually not used when provided because users dislike the vexatious complication of personal authentication.
Some information technology devices have made available a device that functions as a dedicated key and provides a security function, such as preventing access to data on these information technology devices without that key device. In an example disclosed in Japanese Patent Laid-open No. 2003-288328, an explicit key device that allows radio frequency identification is held for personal identification.
Methods using such an explicit key suffer from the possibility of loss and theft of the key itself.